Therapeutic serious game treats mental health problems such as depression, obsessive compulsive disorder, and behavioral disorder by allowing clients to manage and express feelings. These games are developed according to a primary principle of the cognitive behavior therapy that the mental health can be improved by training cognition and behavior with proper stimulation. For those who have difficulties in expressing emotions, stepwise treatment is offered to create a safe emotional environment which induces them to express themselves. The game environment provides affective feelings that encompass physical experiences. In addition, emotional distance is formed between the user and the game environment, and thus even those who have high psychological barriers feel free to express and release their feelings. Game users can experience self-exposure and awareness and gradually construct their self-images, expressing themselves in the virtual world in a continuous and repetitive fashion.